Analysis of the genetic diversity of amaranth (Amaranthus spp.) using ISSR markers

Amaranth is a short-cycle herbaceous plant with high nutritional value and multiple uses as a vegetable, forage, and ornamental; however, its broad phenotypic diversity in Colombia remains uncharacterized. Therefore, the objective of this study was to evaluate the genetic diversity of 50 amaranth genotypes in the department of Boyacá using ISSR (Inter Simple Sequence Repeat) molecular markers. The research identified 194 amplicons-ranging from 14 for ACA to 28 for GT-with 88% polymorphism, sizes between 200 and 3820 bp, and an average PIC of 0.23, allowing the population to be classified into two groups differentiated by morphological traits and the presence of anthocyanins. General genetic parameters revealed an expected heterozygosity (He) of 0.27, a Shannon index (I) of 0.22, a genetic differentiation coefficient (Gst) of 0.16, and a gene flow (Nm) of 2.67, thus demonstrating significant genetic diversity within the evaluated germplasm. For the two established genetic groups, an He = 0.23 was found, with I values of 0.35 and 0.36, respectively. Finally, the AMOVA (Analysis of Molecular Variance) determined that the highest genetic variation occurs at the intrapopulation level, suggesting higher hierarchical levels than those considered in this study. The results obtained may be highly useful for designing conservation strategies and selecting promising amaranth genotypes in Colombia.